Is my ISC bad?

[JMiller]

OK, at the moment i have the most random idle ever. When i start the car the rpms jump to 2000 then fall to 1000 then slowly move up and down between 900 and 1200 rpms. So then i pull out and start to drive and when i push in the clutch the rpms will either fall to about 200 and then jump to 1200 and stay there or they will drop to 1500 and sit there for a few seconds then fall to 900. And today it got even worse, when i push in the clutch the rpms would bounce between 1200 and 2000, it would jump(go through up down cycle) twice per second. This idle thing has been a problem for the past few months. I have no boost leaks, i cleaned the throttle plate, adjusted the throttle cable and set the idle screw thing the way it says on VFAQ. Also Today i tried unpluging the ISC and the rpms sat at 600, at when i started the car with the ISC unplugged they would jump to 1000 then settle at 600. Idle was more consisten with the ISC unplugged. Sorry for typing so much but i wanted to get all the info out there. Thanks in advance.

 

[Silver 95 GST]

try these

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)

Visual Frequently Answered Questions - Home Page

^^under intake

 

[almst 92 tsi]

my car did the same thing and it turned out to be the isc. If you unplugged it and it worked fine then that is more than likely the problem

 

[JMiller]

Yeah i think it is the ISC, also i have looked over the links at the top and once i find my multi meter thing i will test it. But yeah it definantly worked better with the isc unplugged.